Hemp / Canna Industry

For millennia, hemp has been grown outdoors, with growth cycles and viability tied to the whims of Mother Nature. However, the centuries-old Chinese character for hemp depicts two plants under a shelter. Protecting your crop under a greenhouse, it seems, has been a common practice for many thousands of years, and for good reason.

Effectively integrating tried-and-true growing methods with the best in new technologies, and protecting those in the controlled environment of a durable, quality greenhouse, is what we at Gothic Arch Greenhouses know best.

In the 1930s, American’s farmers were pulling out of the Great Depression, with hemp was poised to be a billion-dollar crop. Forward-thinking businessman Henry Ford was a big supporter of hemp for industrial use, but the Marijuana Tax Act of 1937 stalled the growth of the industry.

During WWII, the Hemp for Victory campaign eased the restrictions, and there were many thousands of acres of hemp plants grown across the Midwest, but the tax was reenacted after the war. The 1970s saw President Nixon include hemp in Schedule I of the Controlled Substances Act. Cannabis production moved indoors and under cover, and industrial and agricultural hemp growth was effectively halted.

Those indoor growers learned a lot, many through trial and error, that helped shape how growers produce today. Greenhouses utilize that knowledge, allowing you to control the specifics of your growing environment, which in turn allows you to control your growth, budding, and flowering cycles to any degree that you choose. This helps eliminate problems associated with pollination, seed producing, spikes of THC levels, and drops of CBD levels.

Many cannabis growers choose to grow indoors entirely, with supplemental lighting, irrigation, and nutrient management, and some with soilless growing and hydroponic systems.

CBD producers generally plant at a density of 1,000 to 1,600 plants per acre, planted and tended to as separate plants, much like how ornamental growers plant their crops.

Alternately, hemp that is grown for mass market products such as textiles and bioplastics, is planted in another manner entirely. Many of these growers plant at a density of as many as 400,000 plants per acre, drilled in like wheat. The plants grow tall, with the tops harvested for seed production, and the stalks used for any number of industrial purposes.

In each of these scenarios, a greenhouse can offer protection and create a climate that will ensure a strong showing every time you plan to harvest. From a simple high tunnel to protect from wind, hail, and scorching sunshine to a fully automated light deprivation greenhouse with nutrient injection or hydroponic growing systems, there is a greenhouse that can enhance your production and make the most of your time and resources.

A greenhouse is more energy efficient and conservation-friendly than an indoor grow, and has the additional bonus of harnessing the sun’s full spectrum of light. Not only will you save on the cost of powering lights (which often run 12 to 18 hours a day in a fully indoor grow room), but scientists report that cannabinoid and terpene production are greatest in ambient light. Natural light is much more complex than what even the best grow lights can mimic, though growing lights can be an excellent supplement. A greenhouse can literally catch the sunshine that will help your plants to thrive.

Proper temperature, humidity, and light intensity are critical to producing quality cannabis plants. One of the key benefits of growing indoors is the ability to control these environmental conditions, away from problems like days of cloud cover, too much wind, too much rain, hail, frost, humidity and so on.

A greenhouse harnesses natural sunlight, which builds a full and natural terpene profile. Using artificial light only as a supplement, and not a substitute for sunlight, also has less of an impact on earth’s natural resources. Sun-grown plants require less energy, promoting sustainability by leaving a smaller ecological footprint.

However, there are disadvantages to fully sun-grown, non-greenhouse growing. Producers have to work around the climate and season, while indoor growers can produce year-round. Some growers encourage 18 to even 24 hours of light during vegetative growth, which is impossible with a fully outdoor, non-enclosed growing space.

The ability to control the light cycle indoors allows for multiple harvests annually, while generally outdoor farms are limited to one harvest per year.

Additionally, the harvest time for hemp coincides with hurricane season, which can have effects even far from the coastline as storms dissipate. Harvesting an unprotected crop, drying, and curing hemp biomass before the arrival of a storm can take more labor and can result in losses if not done in time. A physical shelter for your plants can protect your investment in unpredictable weather.

Perhaps the most important factor to consider is pollination. Hemp has been growing outside in a variety of environments for thousands of years, and seeding for propagation is something it is quite good at. However, you're not trying to make seeds if you're growing for CBD. In fact, you're trying to prevent pollination to increase cannabinoid production, and ensuring pollen is not carried on the wind to your plants is impossible outdoors. If you have an upwind neighbor with male hemp plants, then pollination can occur.

Cross-pollination can encourage seed growth and cause THC levels to spike or plunge. Research has found that hemp pollen can travel up to 30 miles from the originating plant. Even if you do not grow from seed, there is no guarantee that your neighbor isn’t. When growing from seed, a seed lot can be littered with male hemp plants, even if the seed is labeled as feminized seed. There is always a large chance that there will still be males in the feminized seed lot, and which means pollen in the air.

Growing in a greenhouse can protect your investment from pollen from males that may be in the air from someone else’s seed lot. If your female plants are pollinated, they will produce flower and seed, rather than only flower. Due to the energy spent producing seeds, the overall CBD concentration within the plant will be reduced, along with the possibility that they will produce more THC than desired.

Nationally, the Department of Agriculture estimates that around 40 percent of outdoor-grown hemp fields fail in the first growing season. 90% of those failures are due to farmers being unable to keep their crops under the 0.3 percent THC limit set for CBD and industrial hemp plants. The controlled environment of a greenhouse can help mitigate external factors which could result in a lost crop.

Another greenhouse advantage is that organic growing methods are easily used in a greenhouse, provided the plants are trained properly using netting to support substantial growth while encouraging airflow, allowing the plants to flourish pesticide and mildew free.

In addition to all of these advantages, a successful greenhouse production can deliver 10 times the yield of an outdoor grow space planted in the same density.

One of the most common greenhouse systems for hemp production is a Blackout or Light Deprivation setup.

Light deprivation methods control how much, and how often plants receive light. Light deprivation greenhouses accomplish this by using blackout material to cover the plants, simulating different seasonal changes. The resulting darkness tricks plants into responding by growing or flowering on command.

Traditionally, hemp is usually planted between March and May in the northern hemisphere and between September and November in the southern hemisphere. It matures in about three to four months. During vegetative growth, plants are bombarded with light that allows them to grow at rapid rates. Some plants grow up to two inches per day during the summer months and, in response to shortened periods of light, only flower in the fall when the daylight hours are shorter.

This is where the absence of light, or light deprivation, comes into play. Light deprivation greenhouses can allow growers to stimulate plant responses as they choose, allowing plants twelve or more hours of uninterrupted darkness every day. Once you start the light deprivation cycle, most plants will begin to react with hormone accumulation in a few days, due to the absence of red evening light. After a few weeks, this triggers flowering and blooming, rapidly producing a higher yield. This process can be repeated multiple times throughout a year, greatly extending your growing season.

Also important to plant health and disease resistance is a complete greenhouse system with a correctly sized temperature control system, with horizontal airflow fans and cooling plates that allow control to reach the most suitable climate and growth zone for your plants.

We offer fully automated light deprivations systems, as well as blackout tarps and hoop houses that can be operated manually. Our automated systems enable you to adjust and pre-program the amount of light, the frequency of light and dark exposure, and the environmental factors that your plants will rely on to bloom. For larger commercial operations, automated systems save a lot of time and can drastically reduce labor costs.

Our many automated light deprivation greenhouses have been specially designed for plants with special lighting needs. With the help of a blackout greenhouse, growers can perfectly control the factors affecting plant growth, such as light, temperature and humidity, shorten the plant growth cycle and maximize its yield. We offer these as single or multi-span units for all levels of grower.

Supplemental grow lighting can be a major part of producing a profitable yield. Correct lighting is important for the health of almost all plants. Without proper spectrum and intensity, your crops are less likely to thrive.

The type of lighting you will need greatly depends upon the intended market for the plants that you’re growing. Knowing the lighting requirements for medical versus CBD oil production versus hemp protein production, for example, is key to creating an optimum growing environment. Gothic Arch offers a range of high- quality lighting for every need.

• Compact Florescent (CFL) and T5 Florescent lights are amongst the best lights for clones, seedlings and young plants. Bigger lights must be kept far away from young plants to avoid burning them, which ends up wasting a lot of light and energy, but by using smaller lights like fluorescents while plants are still short, you can save quite a bit of money on electricity during those first few weeks compared to using a high-powered grow light.
• High Pressure Sodium (HPS) lights are the most effective High Intensity Discharge (HID) light available. These lights put off double the light compared to other lighting systems and have high yellow, orange and red spectrums to promote flowering.
• Light Emitting Diode (LED) lights emit nearly double the lumens per watt than fluorescent or HID lights while using less energy and putting off less heat. This traditionally more compact lighting system can be customized to put out as specific wavelength of light, making it easy to adjust based on your growing needs.M
• Light Emitting Plasma (LEP) lights emit full spectrum light while using almost 50% less energy than HID lamps resulting in lower operational costs. It also has a longer life span as compared to other grow lights.

Hydroponic growing has long been an important technique in hemp production. From the early basic days of hand-watering pots of medium with nutrients, to the newer, sophisticated systems of automated pumps, timers, and reservoirs, the aim is the same: to provide your plants with the fuel they need to flourish.

The disadvantages of growing exclusively in soil are:

• You may not be able to recycle your soil
• Soil is susceptible to pest problems
• It can be difficult to determine proper amount of nutrients
• You need to carefully monitor soil pH
• It can be easy for soil changes to go undetected which lead to spikes in THC
• Therefore, your soil quality significantly influences the final product

With Hydroponic growing, you use small amounts of grow media that can often be reused, while also precisely controlling what nutrients the plants are receiving and ensuring proper pH levels. With such levels of control, growers find that their buds are bigger and healthier, and fluctuations in phytocannabinoids are reduced.

Hydroponic greenhouses contain systems such as NFT channels, a Dutch bucket system, or ebb and flow benching to give larger-scaled growers even more environmental control over their crop. Adding proper ventilation and lighting control to a hydroponic greenhouse increases yield and plant viability to take growers to the next level with ease.

Growers need to be aware that plant stresses like drought, flooding, excessive nutrients, not enough nutrients, heat, cold, etc. can result in THC spikes, which could result in losing a viable CBD harvest. About 10% of hemp fields are 'going hot' in the current cycle, according to the USDA. This is a serious risk to hemp producers, so mitigating this risk is vital.

Being able to control nutrients within a hydroponic system offers an optimum environment to control any nutrient and environmental spikes that are unrelated to external cross-pollination.

Other important factors in creating the ideal medical, CBD, or hemp greenhouse structure include the integration of modern agricultural technology, in order to create a systematic and efficient growing approach.

In addition to our greenhouse structures, we also offer:

• Odor Misting- these high-pressure fog systems are uniquely suited to provide many benefits for growers. In addition to providing safe, eco-friendly odor elimination, fog provides the perfect combination of humidity and cooling that optimizes plant growth.
• Odor sensors- these enable you to control when the odor suppression system is activated based on time, air temperature, and wind direction and speed
• Odor Control Vent Panels - Activated carbon and molecular filtration solutions work with ventilation to meet local odor control ordinances
• CO2 Generators - Carbon dioxide (CO2) is essential for plants to complete the process of photosynthesis to convert CO2 into energy. High levels of Carbon Dioxide in a growing space can result in stronger plants with increased yields
• Nutrient Injectors- Hand-measuring each batch of nutrient solution is time consuming and has a high potential for error. A precise fertilizer injection system to reduce mixing time and reduce the risk of operator error. You can decrease your fertilizer mixing time by more than 90%.
• Heating/Cooling- Creating the optimum growing environment means managing temperature to ensure a constant comfortable climate for your plants.
• Shade Systems- Shade cloth, aluminet, and light deprivation shades can each play an important role in controlling the sunlight, solar gain, and heat transfer in your greenhouse.
• Environmental Controls- When growing year-round, some form of environmental control is necessary for just about any grower. Automated environmental controls make it easy for you to maintain control of your greenhouse environment with the touch of a button.
• Dehumidification- Improper humidity levels can cause powdery mildew, botrytis (or bud rot), decreased yields, and overall poor plant health. Dehumidification, when needed, can produce bigger, healthier plants.
• Irrigation/Fertilization- The cycle of an indoor grow is around 3 months, with the first month for the plants’ vegetative growth and the next 2 months for flowering. During this time plants require water daily and fertilizers every few days, so irrigation will become a repetitive task that can end up tiring all but the most dedicated grower. When time is at a premium, automatic irrigation and fertilization can be a major help.
• Insect Screens- Keeping pests out of your greenhouse can save your crop. Insects can often bring pollen with them, which can ruin a crop quickly.
• Benching Systems- from simple growing tables to rolling tabletops and ebb and flow benches, greenhouse bench systems are essential to your growing set up.
• Radiant Heating- The even heat distribution of radiant heating results in fewer cool spots, meaning that more heat remains at the root mat instead of sporadically spreading throughout the greenhouse to fill cold spots. With steady heat, plants are able to thrive.
• Advanced Grow Techniques- set up a SOG (or Sea Of Green) or ScrOG (or Screen Of Green) grow space, implement advanced Hydro or Aeroponics into your greenhouse- we have the tools to help you move to a new level of growing.
• Greenhouse Automation Systems- Fully automated greenhouse systems of all kinds are available to assist with every stage of the production process, from seed to harvest, clone to curing. A sealed greenhouse can create the perfect conditions for maximum benefit to your crop, because you are effectively controlling the internal greenhouse environment in all stages of growth. This is a key to success, as stated by many of the largest commercial growers in the industry.

Sophisticated fertigation systems can be integrated with a computerized system to control grow lighting, temperature & humidity, air exchange, CO2 dosing, misting and fogging where required.

There are soil sensors for both soil and soilless media to read the temperature, EC and moisture at the root zone of plants, and programable ebb and flow tables can be coupled with a closed ventilation system that provides fresh air exchange, keeps humidity at acceptable levels, and filters in-bound contaminants and out-bound odors. The possibilities are both remarkable and endless.

So where is the hemp industry headed?

Industrial hemp farming is seeing renewed interest as a viable agricultural crop. We are now seeing trends in:

• Hemp oil
• Hemp cake as a protein
• Hemp-strengthened building materials
• Baler twine—this is an industry served almost exclusively by petroleum-based plastic twine
• Bioplastics-- reliable supply would be needed to supply the large players in this industry

To meet the needs of the future, hemp production will need to hold itself to the highest agricultural standards. As the industry matures, consistency and predictability will be required to standardize a medical product and to gain approval in the pharmaceutical sphere. Greenhouses are essential to this process.

Standardization is necessary for a reliable, reproducible product that can be researched during clinical trials. To achieve such standards and protect plants from unwanted influences, there must be regularity and consistency in every aspect of the growing procedure—water, light, humidity, pest management, etc.

This can be challenging for even the most meticulous outdoor cultivator, as it is difficult to control humidity, fungal infestation and other environmental factors that can adversely affect an outdoor crop. Combining the best of outdoor growing with the micro-climate of a greenhouse structure will move production into the future.

Top-quality production techniques will be key in pushing the industry forward, and by exploring how the proper greenhouse and greenhouse technology will help your own efforts, Gothic Arch Greenhouses hopes to assist in your endeavors.